I completely misunderstood passkeys.
Just came back from doing a bit of research and apparently I can use Bitwarden to generate and store passkeys.
I have been dismissing the entire concept because I assumed it had to do with hardware keys, which I would never trust. But if it's bitwarden, then I can easily do a backup, and that would be very reliable.
I think I'm going to start using passkeys... :D
The standard allows sites to ban things like bitwarden over time.